This is disabled by default; use the security/php5-hash port:cd /usr/ports/security/php5-hash ; make install clean(do not use the security/pecl-hash port as in the past, see the /usr/ports/UPDATING post from 20081211)

Some tests with mhash and hash revealed on my machine that hash needs more than twice as long to create a hash than mhash. The average of one million cylces of Haval128, Haval256, Gost, CRC32, MD5, SHA1 and SHA256 was 450ms for mhash and 1150ms for hash.